Diagnostic value comparison of the combination of prostate-specific membrane antigen-body positron emission tomography/magnetic resonance imaging and prostate health index with each alone in early diagnosis of prostate cancer

Objective This study aimed to figure out whether the combination of prostate health index (PHI) and prostate-specific membrane antigen (PSMA)-positron emission tomography/magnetic resonance imaging (PET/MR) could improve the diagnostic accuracy for prostate cancer (PCa) than that of each individual method used alone. Methods In this prospective, observational study, 41 patients who underwent systematic prostate biopsy between June 2019 and September 2022 were enrolled. Both the PHI test and 18F-PSMA-1007-PET/MR were performed prior to biopsies. The diagnostic accuracy of different models was compared by logistic regression, area under the curves (AUC) of the receiver operating characteristic and net reclassification improvement (NRI) index. Results Among the 41 patients, 14 (34.1%) were pathologically diagnosed with PCa. PHI in PCa group was significantly higher than that in benign group (44.4 vs. 35.0, p=0.048). Similarly, all the patients in PCa group received the positive results of 18F-PSMA-1007-PET/MR, of which the positive rate was significantly higher than those in bengin group (100% vs. 62.96%, p<0.05). The 18F-PSMA-1007-PET/MR provided additional diagnostic value to PHI (AUC: 0.802 vs. 0.692, p=0.025). However, there was no significant difference between the combination model and the 18F-PSMA-1007-PET/MR alone (AUC 0.802 vs. 0.685, p=0.071). The optimal PHI cutoff of the combination model is 32, with which the model could significantly reduce unnecessary biopsy (NRI: 22.22%, 95% confidence interval: 6.54–37.90, p=0.005). But among patients with PHI≥43.5, there was no significant difference between the combination model and PHI alone (NRI: 11.11%, 95% confidence interval: −0.74–22.97, p=0.066). Conclusion The combination of PHI and 18F-PSMA-1007-PET/MR outperforms PHI alone for predicting PCa, especially in avoiding unnecessary biopsy. However, for patients with PHI≥43.5, the addition of 18F-PSMA-1007-PET/MR to PHI does not yield additional benefits.